DATA Step, Macro, Functions and more

difference between SET and APPEND

Posts: 70

difference between SET and APPEND

Can anybody tell me the differnces between SET and APPEND.Thanks in advance

Posts: 42

difference between SET and APPEND

SET statement is used to read Input/Records.

APPEND is A proc in SAS.

PROC APPEND BASE=SAS-data-set DATA=SAS-data-set;
names the data set to which you want to add observations.
names the SAS data set containing observations that you want to append to the end of the
SAS data set specified in the BASE= argument.

PROC APPEND reads only the data in the DATA= SAS data set, not the BASE= SAS
data set. PROC APPEND concatenates data sets even though there may be variables in
the BASE= data set that do not exist in the DATA= data set.
When the BASE= data set contains more variables than the DATA= data set, missing
values for the additional variables are assigned to the observations that are read in
from the DATA= data set and a warning message is written to the SAS log.

Let me know if you have any questions.


S Ravuri.

Super User
Posts: 10,516

difference between SET and APPEND

Proc Append won't add any variables that do not exist in the base dataset. However it is faster for adding records than using SET in a datastep.

Posts: 70

difference between SET and APPEND

thank....u.I have one doubt we can add any no of datasets at a time.In the same way is can we add more than one datasets at a time using APPEND .I tried but i didnt get is there any way.

If we wanna do append using APPEND/SET there must be same variables names,with out a same variable names we cant append is this right?

Thanks & regards


Senior User
Posts: 1

Re: difference between SET and APPEND

You can use a macro to append multiple datasets together using PROC APPEND.

But SET statement will do the trick without the macro as well.

It'll take a little bit of time to code the macro but overall efficiency of the MACRO will be better compared to SET statement with multiple datasets.



(PS: I know this post is way too old)

Regular Contributor
Posts: 233

difference between SET and APPEND

Ask a Question
Discussion stats
  • 5 replies
  • 5 in conversation